Study Questions:

Is there an association between beta-blocker use and cardiovascular mortality in patients with stable coronary artery disease (CAD)?

Methods:

Data were analyzed from 4,184 outpatients included in a prospective cohort study on stable CAD. Two groups were formed based on beta-blocker use at enrollment. Two propensity score analyses were performed to control for differences in covariates: one with adjustment among the entire cohort, and the other with propensity score matching. The outcome variable was cardiovascular mortality after a 2-year follow-up interval.

Results:

There were 3,320 patients with beta-blocker use. Younger age, hypertension, diabetes, prior myocardial infarction, multivessel CAD, prior coronary revascularization, prior stroke, prior hospitalization for heart failure, and a low left ventricular ejection fraction were associated with beta-blocker use. Clinical follow-up data were obtained for 4,149 patients (99.2%). When adjusted using propensity score, beta-blocker use was associated with a hazard ratio (HR) for cardiovascular mortality of 0.64 (0.42-0.98) in the whole cohort (p = 0.04). After one-to-one propensity score matching, both groups (n = 839 in each group) were well matched for covariates. The cardiovascular mortality rate in the propensity-matched cohort was significantly lower in patients with beta-blocker use with an HR of 0.43 (0.22-0.82) (p = 0.011). Noncardiovascular mortality was similar in both groups. These results were consistent across different subgroups.

Conclusions:

In this observational study of patients with stable CAD, the use of beta-blockers was associated with a lower risk of cardiovascular mortality.

Perspective:

Therapy with a beta-adrenergic antagonist has been long associated with lower cardiovascular mortality in the first years following acute myocardial infarction (MI). However, data supporting this predate current acute revascularization strategies for management of acute MI. Further, the beneficial effects of beta-blockers might have been extrapolated to indefinite use after acute MI, and to use in patients with CAD, but no prior MI. This study suggests that the use of beta-blockers is associated with lower cardiovascular mortality among patients with stable CAD. However, another recently published report suggests that the benefit of beta-blockers is limited to patients with prior MI (Bangalore S, et al., Circ Cardiovasc Qual Outcomes 2014;7:872-81 [doi: 10.1161/circoutcomes.114.001073]).